NAME
Devel::Timer - Track and report execution time for parts of code
SYNOPSIS
use Devel::Timer;
my $t = new Devel::Timer();
$t->mark("first db query");
## do some work
$t->mark("second db query");
## do some more work
$t->mark("end of second db query");
$t->report();
DESCRIPTION
Devel::Timer allows developers to accurately time how long a specific
piece of code takes to execute. This can be helpful in locating the
slowest parts of an existing application.
First, the Devel::Timer module is used and instantiated.
use Devel::Timer;
my $t = new Devel::Timer();
Second, markers are placed before and after pieces of code that need to
be timed. For this example, we are profiling the methods
get_user_score() and get_average_user_score().
$t->mark("first db query");
&get_user_score($user);
$t->mark("second db query");
&get_average_user_score();
Finally, at the end of the code that you want to profile, and end marker
is place, and a report is generated on stderr.
$t->mark("END");
$t->report();
Sample report:
Devel::Timer Report -- Total time: 0.3464 secs
Interval Time Percent
----------------------------------------------
02 -> 03 0.3001 86.63% second db query -> END
01 -> 02 0.0461 13.30% first db query -> second db query
00 -> 01 0.0002 0.07% INIT -> first db query
The report is output using the method Devel::Timer::print() which
currently just prints to stderr. If you want to send the output to a
custom location you can override the print() method. The initialize()
and shutdown() methods can also overridden if you want to open and close
log files or database connections.
e.g.
package MyTimer;
use strict; use Devel::Timer; use vars qw(@ISA);
@ISA = ("Devel::Timer");
sub initialize { my $log = "/tmp/timer.log"; open(LOG, ">>$log") or
die("Unable to open [$log] for writing."); }
sub print { my($self, $msg) = @_; print LOG $msg . "\n"; }
sub shutdown { close LOG; }
You would then use the new module MyTimer exactly as you would use
Devel::Timer.
use MyTimer;
my $t = new MyTimer();
$t->mark("about to do x");
$t->mark("about to do y");
$t->mark("done y");
$t->report();
SEE ALSO
Time::HiRes
AUTHOR
Jason Moore - jmoore@sober.com